The Etiology and Treatment of Anemia

Abstract

Anemia is a significant global health challenge. While the subject of anemia has been well-studied, critical questions regarding its causes and treatment remain. Chapter 1 investigates the optimal schedule, duration, dose, and co-supplementation regimen for iron supplementation as a treatment of anemia among children. A systematic review and meta-analysis of randomized controlled trials was conducted. A total of 123 eligible trials were identified. Frequent (3-7/week) and intermittent (1-2/week) iron regimens were similarly effective at increasing hemoglobin and decreasing anemia, iron deficiency, and iron deficiency anemia (p-heterogeneity>0.05). Varying durations of supplementation showed similar benefits after controlling for baseline anemia status, except for serum ferritin, which showed larger increases with longer duration of iron (p=0.04). Moderate- and high-dose supplements were more effective than low-dose supplements at improving hemoglobin (p=0.03) and ferritin (p=0.003). Co-supplementation of iron with zinc or vitamin A modestly attenuated impacts for anemia (p=0.048) and hemoglobin (p=0.03), respectively, although benefits remained even in co-supplemented groups. In Chapter 2, the risks and benefits of iron supplementation among HIV-infected children are examined. A prospective cohort study of 4,229 children were observed for a mean follow-up of 2.9 years. After adjustment for time-varying clinical covariates, time-varying iron supplementation was associated with a 2.87 times higher hazard rate of mortality (95% CI: 1.70, 4.87) and a 1.48 times higher hazard rate of HIV disease stage progression (95% CI: 1.10, 1.98). Iron supplementation was also associated with a lower rate of anemia persistence (HR=0.47; 95% CI: 0.37-0.61). No differences in the association between iron supplementation and clinical outcomes were observed by ART or anemia status. Chapter 3 quantifies the proportion of anemia cases attributable to selected nutritional, infectious disease, and other risk factors. A population-based cross-sectional study of women, men, and children was conducted. Low serum ferritin contributed to 11% (-1, 22) of anemia cases among women, 9% (0, 17) among men, and 19% (3, 33) among children. The proportion of anemia attributable to low serum folate was estimated at 25% (4, 40) among women and 28 (11, 42) among men. Inflammation and malaria were responsible less than one in ten anemia cases.